added custom template field to hostelement and element on backend
fixes, migration
added support for the custom template flag in the editor. Disabled changing of the template for prepared and running elements.
Fixed language of timespan strings
Fixed dhcp for openvz
Merge pull request #350 from dswd/fix-dhcp

Fixed dhcp for openvz
Merge pull request #347 from dswd/fix-lang

Fixed language of timespan strings
disabled uploads via HTTPS.
changed custom_flag db entry from column to attribute
Merge branch 'master' into custom_template_flag

Conflicts:
	backend/tomato/elements/generic.py
Merge pull request #351 from t-gerhard/https_hotfix

disabled uploads via HTTPS.
Merge branch 'master' of ssh://github.com/GLab/ToMaTo into custom_template_flag
Merge pull request #343 from t-gerhard/custom_template_flag

Custom template flag
Released hostmanager 3.1.1